1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner, and more particularly to a chemical mechanical polishing conditioner which may provide deformation compensation for a substrate.
2. Description of Related Art
Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization due to its ability to achieve whole planarization.
During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer is removed by a polishing pad in contact therewith (or semiconductor element) with optional use of slurry, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface; and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. However, during curing of the abrasive layer, the surface of the substrate may be deformed because of the difference in thermal expansion coefficient between the abrasive layer and the substrate, thus destroying flatness of the abrasive particles of the conditioner and thereby adversely affecting the polishing efficiency and service life of the conditioner.
Conventionally, the surface flatness of a chemical mechanical polishing conditioner is typically controlled by two ways. One way is to dispose the abrasive particles and the binding layer on the surface of the substrate, followed by pressing down the abrasive particles using a rigid plate to embed and fix the abrasive particles into the abrasive layer such that the surfaces of the abrasive particles and the rigid flat may have the same flatness. Another way is to dispose the abrasive particles into a recess of a mold, followed by covering the non-working surface of the abrasive particles with a binding layer and a substrate, and performing heat curing, and finally, flipping the mold upside down to separate the cured chemical mechanical polishing conditioner from the recess of the mold. However, in the above two methods for manufacturing the chemical mechanical polishing conditioner, during heat-curing the binding layer, the difference in thermal expansion coefficient between the binding layer and the substrate may result in deformation of the substrate of the chemical mechanical polishing conditioner after curing, which in turn results in deformation of the surface of the chemical mechanical polishing conditioner and destroys the flatness of the abrasive particles of the conditioner.
Therefore, what is needed is to develop a chemical mechanical polishing conditioner with surface flatness, which cannot only avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, but also control the surface flatness of the chemical mechanical polishing conditioner.